The analgesic efficacy of continuous presternal bupivacaine infusion through a single catheter after cardiac surgery.

Background: Median sternotomy, sternal spreading, and sternal wiring are the main causes of pain during the early recovery phase following cardiac surgery. Aim: This study was designed to evaluate the analgesic efficacy of continuous presternal bupivacaine infusion through a single catheter after parasternal block following cardiac surgery. Materials and Methods: The total of 40 patients (American Society of Anesthesiologist status II, III), 45–60 years old, undergoing coronary – artery bypass grafting were enrolled in this prospective, randomized, double‑blind study. A presternal catheter was inserted with continuous infusion of 5 mL/h bupivacaine 0.25% (Group B) or normal saline (Group C) during the first 48 postoperative hrs. Primary outcomes were postoperative morphine requirements and pain scores, secondary outcomes were extubation time, postoperative respiratory parameters, incidence of wound infection, Intensive Care Unit (ICU) and hospital stay duration, and bupivacaine level in blood. Statistical Methods: Student’s t‑test was used to analyze the parametric data and Chi‑square test for categorical variables. Results: During the postoperative 48 h, there was marked reduction in morphine requirements in Group B compared to Group C, (8.6 ± 0.94 mg vs. 18.83 ± 3.4 mg respectively, P = 0.2), lower postoperative pain scores, shorter extubation time (117 ± 10 min vs. 195 ± 19 min, respectively, P = 0.03), better respiratory parameters (PaO2/ FiO2, PaCO2 and pH), with no incidence of wound infection, no differences in ICU or hospital stay duration. The plasma concentration of bupivacaine remained below the toxic threshold (at T24, 1.2 ug/ml ± 0.3 and T48 h 1.7 ± 0.3 ug/ml). Conclusion: Continuous presternal bupivacaine infusion has resulted in better postoperative analgesia, reduction in morphine requirements, shorter time to extubation, and better postoperative respiratory parameters than the control group.

The efficacy of caudal dexmedetomidine on stress response and postoperative pain in pediatric cardiac surgery.

Aims and objectives: We studied efficacy of caudal dexmedetomidine (DEX) on attenuation of perioperative stress response and postoperative pain in pediatric patients undergoing cardiac surgery. Materials and Methods: Forty patients, (ASA II, III), 1-3-years old were randomly allocated into two groups; group BD received caudal bupivacaine 0.25%, 2.5 mg/kg and DEX 0.5 μg/kg and group BF received bupivacaine 2.5 mg/kg and fentanyl 1 μg/kg. Results: Serum cortisol and blood glucose levels increased in both groups but increases were significantly less in group BD. Poststernotomy cortisol level (ug/dl) was 55.3 ± 5.1 vs. 90.4 ± 6.5; after cardio-pulmonary bypass (CPB) 84.1 ± 6.2 vs. 153.1 ± 8.5; after operation 78.3 ± 8.1 vs. 150.2 ± 9.8. Poststernotomy blood glucose level (mg/dl) was 93.6 ± 7.2 vs. 125.6 ± 5.5; after CPB 115.3 ± 3.7 vs. 175.3 ± 10.4; and after operation 97.3 2 ± 3 vs. 162.2 ± 12. Heart rate and mean arterial pressure decreased significantly after caudal block in group BD relative to the baseline and compared with group BF ( P < 0.05). Group BD had lower pain scores at first hour 2 ± 0.7 vs. 3 ± 1.1 ( P = 0.04); second hour 1.9 ± 0.5 vs. 3.7 ± 0.8, ( P = 0.008); fourth hour 2.4 ± 0.8 vs. 4.3 ± 0.5 ( P = 0.03); and eighth hour 2.5 ± 0.5 vs. 4.2 ± 1.1 ( P = 0.03). Conclusions: Caudal DEX attenuated stress response to surgical trauma and provided better postoperative analgesia.